NU29-900-ECMA-HB1 bearing: complete specifications & equivalents
The NU29-900-ECMA-HB1 is a ISO 15 radial bearing sized 900 x 1180 x 165 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 900 mm |
| Outer diameter D | 1180 mm |
| Width B | 165 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 5280 kN |
| Basic static load rating C0 | 12500 kN |
| Fatigue load limit Pu | 800 kN |
| Reference speed (thermal) | 430 rpm |
| Limiting speed (mechanical) | 560 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 514000 g |
| Manufacturer designation | SKF NU 29/900 ECMA/HB1 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & NU2900-series range
| Bore d | 35.433 in |
|---|---|
| Outer diameter D | 46.457 in |
| Width B | 6.496 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 140 mm |
| Smallest bore in NU2900-series | 420 mm |
| Largest outer diameter in NU2900-series | 1180 mm |
| Width range across NU2900-series | 82–165 mm |
| Bore position in NU2900-series (smallest first) | 7 of 7 |
| Bore above smallest NU2900-series size | 480 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU29-900-ECMA-HB1 model number is decoded
SKF NU 29/900 ECMA/HB1 is a single-row caged cylindrical roller bearing sized 900×1180×165 mm — a dimension series 29 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 900 mm seat is about 5.87 kN/mm, typical of dimension series 29 (compact OD, normal width); use C0 12500 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.
Typical equipment & failure modes
Common applications
- offshore drawworks shafts
- large rolling-mill drive trains
- marine propulsion line shafts
- heavy turbogenerator rotor supports
Known failure patterns
- inner-ring raceway spalling from overload or contamination in the line-contact hertz zone
- outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating
- cage pocket wear from roller skew at light load
- cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- Do not use a NU bearing where axial load must be carried — the design carries radial load only
- The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/900, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/900 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 5280/12500 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification.
Frequently asked questions
What are the dimensions and catalogue data of NU29-900-ECMA-HB1?
SKF NU 29/900 ECMA/HB1 is a single-row caged cylindrical roller bearing with 900 mm bore, 1180 mm OD and 165 mm width per ISO 15. SKF lists C 5280 kN, C0 12500 kN, Pu 800 kN, reference speed 430 r/min and limiting speed 560 r/min, mass about 514000 g.
What does the NU designation and ECMA/HB1 suffix mean?
The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable.
Can NU29-900-ECMA-HB1 take axial load and locate the shaft?
No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty.
How does NU29-900-ECMA-HB1 compare with the other executions in the same envelope?
The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number.
What limits the service life of this bearing most often?
Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.